(a) Field
The present invention relates to a bidirectional interface circuit and a battery management system including the same.
(b) Description of the Related Art
By connecting in series a plurality of battery cells, a battery stack is formed, and power is supplied from the battery stack to a load. The number of a plurality of battery cells is determined according to a load. For example, as a capacity of a load increases, the number of a plurality of battery cells increases.
Because the number of battery cells in which a battery management IC may control is limited, as the number of battery cells that are included in the battery stack increases, the number of battery management ICs increases. Each of a plurality of battery management ICs is connected to a corresponding plurality of battery cells in a battery stack and manages corresponding battery cells. In this case, a plurality of battery management ICs are connected to each other to form a stack structure.
In this case, communication for notifying an abnormal state between adjacent battery management ICs is necessary.
That is, in a plurality of cells that are connected to a battery management IC, when an abnormal state (e.g., over-voltage, low voltage) is sensed, the battery management IC transmits a signal notifying an adjacent another battery management IC of an abnormal state and receives a signal notifying an abnormal state that has occurred in an adjacent another battery management IC.
For example, when a plurality of battery management ICs are connected, the battery management ICs each include two pins for transmitting and receiving a signal to and from an adjacent battery management IC in an upper direction and two pins for transmitting and receiving a signal to and from an adjacent battery management IC in a lower direction. That is, a battery management IC includes four pins for communication with adjacent another battery management IC.
The above information disclosed in this Background section is only for enhancement of understanding of the background and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.